07 June 2013

Diet and Cognition

Welcome back. As my life ebbs by, I fall apart physically, but I seem to be doing ok…uh…what was I…ah, mentally. (Sorry; it’s nothing to joke about.)

There’s been a boatload of research on mental decline with age, but of the recent work, I was particularly interested in papers relating diet to cognition--mental processes such as perceiving, recognizing, conceiving and reasoning.

Good diet is, of course, well documented for physical fitness, yet research is showing that good diet, particularly the Mediterranean diet, might also improve mental health.

Mediterranean Diet

As an undergraduate, I subsisted for two years on pizza (various toppings) and hot meatball subs from the Italian restaurant across the street from my shared Collegetown apartment. Mediterranean cuisine varies; however, that diet would nowhere be considered a Mediterranean diet.

According to Oldways, a nonprofit food and nutrition education organization, the classic Mediterranean diet was introduced in 1993 by Oldways, the Harvard School of Public Health, and the European Office of the World Health Organization. Oldways’ website presents the diet in detail, with recipes and additional resources, and the diet is laid out on many other websites as well as in cookbooks.

Research on Mediterranean Diet and Cognition

Two recent papers indicating a Mediterranean diet might slow cognitive decline were published about the same time.

A University of Alabama effort analyzed data on nearly 17,500 participants, average age 64; the data had been collected during a 2003-2007 U.S. study of geographic and racial factors in strokes. How closely each participant followed a Mediterranean diet was scored from questionnaires; thinking and memory skills were measured at baseline and annually using a six-item screening test.

The analysis found that closer adherence to the Mediterranean diet was associated with a 19 percent lower likelihood of cognitive impairment. This was true regardless of racial or regional difference, failing only for those with diabetes.

The second paper reported research that compared a low-fat diet versus two versions of a Mediterranean diet for slowing cognitive decline. This University of Navarra, Spain, study tracked almost 525 participants, average age mid-70s, all of whom had high vascular risks due to type-2 diabetes or a combination of factors.

Comprehensive cognitive testing after 6.5 years determined that those on either version of the Mediterranean diet (extra virgin olive oil or extra mixed nuts) scored higher than those on the low-fat diet.

Wrap Up

I’ve no doubt you will now shift immediately to or toward a Mediterranean diet. While you’re at it, go learn another language.

If I had had more space, I was going to get into studies that found bilinguals have higher levels of cognitive control than monolinguals. The latest research, for example, provides direct evidence of a neural basis for bilingualism slowing cognitive decline.

I’ve always been in awe of anyone like close friend Ben, in Denmark, who slips back and forth effortlessly among 4 or 5 languages, but I’m a lost cause with languages. Knowing now that bilingualism boosts cognition, I guess I’m also envious of Ben-- while I can still remember him. Are you reading this, Ben? How’s the Mandarin coming along?